Common tricks identified in the study include stirring arguments between them, banning them from seeing each other, not passing on telephone messages and confiscating or hiding mobile phones.

Some parents admitted that they have listened in to private telephone conversations, while others have gone so far as to follow their offspring to see who they are meeting and confront their lovers, the Daily Mail reported.

Mothers emerged as the biggest culprits, with one in three admitting they have won a battle to split their child from someone they considered “not good enough.”

Only one in four fathers said the same thing.

The study of 2,000 parents found one in three has disapproved of someone their child is dating.

Around one in ten admitted disliking them so much that they “did anything they could” to try and break up the young lovers.

But one in five owned up to less extreme forms of sabotage to discourage the relationship, including not passing on messages, grounding their children and simply trying to talk them out of it.

The study found three quarters of parents have kept a close eye on their children’s fledgling relationships, with almost half admitting the idea of their offspring being in one really bothers them.

More than one in four believed their child’s partner was not good enough for them, while 24 percent thought the person their offspring had fallen for was “too old.”

The research was commissioned by the publisher Penguin to mark the release of the second book in a romantic series for teenage readers, ‘Girl Heart Boy: Rumour Has It.’

The study also found parents’ spying went beyond relationships, with 30 percent admitting to snooping on all areas of their teenagers’ lives, for example through Facebook.